Flange sleeve, method for the production thereof and bending tool for producing flanges on a sleeve

ABSTRACT

Disclosed is a flange sleeve ( 10 ) comprising at least one flange ( 3 ) formed thereon, having no gap at the joint or having a controllably adjusted width of the gap at the joint. The flange ( 13 ) has two crowding recesses ( 16, 16′, 16″, 16′″ ) at least in the metal coating thereof in at least two points distributed over the flange in the direction of the periphery. According to the method for producing said flange sleeves ( 10 ), the edge of the flange is bent. At least two crowding recesses in at least two points distributed over the flange in the direction of the periphery are made at least in the metal coating thereof, said recesses preferably being made by bending the edge of the sleeve. The invention also relates to a bending tool and a bending device.

[0001] The invention relates to a flanged bush, in particular a flanged bush for plain bearings with at least one flange formed thereon, according to the precharacterizing clause of claim 1, a method for the production thereof according to the precharacterizing clause of claim 9 and a bending die according to the precharacterizing clause of claim 13.

[0002] The invention further relates to a bending device including a bending die.

[0003] Flanged bushes, which comprise either one or two flanges, are known in a very wide range of sizes, with diameters ranging from centimeters to decimeters. The materials used depend on the intended application, wherein the bush material may be of single- or multilayer construction. Single-layer bushes are known as solid bushes. Bushes of multilayer construction generally comprise a backing material and an overlay. The overlay may consist of a metal alloy or plastics. The invention relates to all flanged bushes, irrespective of their dimensions, intended purpose and the materials used, with the one reservation that the flanged bushes have to comprise at least one metallic layer.

[0004] To produce flanged bushes, bearing sleeves or bushes are used whose edge is bent round into a flange in a further operation. A method which is currently conventional is bush wrapping, wherein a flat strip portion, the so-called blank, is wrapped round to form a bush or sleeve.

[0005] In the case of wrapped bearing bushes, it is generally necessary for the butt joint to be closed when the bush is fitted, while the butt joint is generally not fully closed when the bearing bush is not fitted, since the material springs open to a greater or lesser degree depending on the method used to produce the bush (c.f. DIN 1494, part 1, June 1983, p. 1).

[0006] Production methods for wrapped bushes are known and are described for example by Dipl. -Ing. Hugo Kotthaus in “Betriebstechnisches Taschenbuch”, vol. 2, 7th edition, Karl Hanser Verlag Munich, 1967, pp. 212 ff.

[0007] To close open butt joints, it is proposed in DE-OS 2317564 to heat the bushes and simultaneously to prevent an increase in diameter as a result of thermal expansion.

[0008] Both with this known method and with a shaping method described in DE-PS 517530, it is possible to close the butt gap in bushes.

[0009] However, if such prefabricated bushes are shaped into flanged bushes, by bending round the edge of the bush, the butt joint opens up again, wherein the gap width may assume considerable dimensions depending on diameter and flange width.

[0010] Flanged bushes with gaps can only be fitted using special tools, with which the flanged bush is compressed through the application of considerable force, wherein the flanged bush may possibly also warp, leading in turn to damage to the flanged bush.

[0011] Relatively small flanged bushes, which are transported in large numbers in cartons as loose cargo, may become hooked together, often resulting in a chain of several flanged bushes. The buyer has to separate the flanged bushes laboriously and generally by hand before fitting them. There has therefore long been a desire for flanged bushes with closed butt joints.

[0012] In flanged bushes, a closed butt joint could hitherto only be achieved by welding a ring forming the flange to a bush. The disadvantage of this method is that welding is more expensive than bending of the bush edge.

[0013] It is therefore the object of the invention to provide a bush with closed or extensively closed butt joint which does not cost any more to produce than the conventional flanged bushes obtained by bending.

[0014] A further object of the invention is to provide a suitable method and an appropriate device or bending die.

[0015] As far as the method is concerned, the object is achieved in that, at at least two points distributed around the flange in the circumferential direction, material-displacing recesses are formed at least in the metal layer of the flanged bush.

[0016] It has surprisingly been demonstrated that the material displacement caused by the formation of the recess stretches the flange in the circumferential direction in such a way that the butt gap is closed.

[0017] The formation of material-displacing recesses is a cost-effective method, especially if the recesses are produced, as preferred, by stamping.

[0018] The recesses may be formed in the inner and/or outer surface of the flange.

[0019] Where the recesses are formed depends on the structure of the flanged bush, the material and the intended application. If the flanged bushes are intended for diesel engines, for example, the bush consists as a rule of a metallic backing material, on which at least one overlay has been applied. In order not to damage the overlay by the formation of material-displacing recesses, the recesses are preferably formed in the inner surface of the flange.

[0020] If, in the case of coated bushes, the recesses are to be formed additionally or solely in the outer surface of the flange, the recesses have to extend as far as into the metallic backing layer, since otherwise not enough of the material causing the springing-open effect is displaced.

[0021] The recesses are preferably produced when bending the bush edge. Incorporation into the bending process has the advantage that no additional method step is necessary, such that the production costs do not increase relative to conventional flanged bushes. If the material-displacing recesses are formed in the flange during bending, the butt joint cannot open in the first place.

[0022] Closure of the butt joint may be controlled or the width of the butt joint may be specifically adjusted, depending on the intended purpose of the bush, by means of the size, number, shape and depth of the recesses.

[0023] The flanged bush according to the invention, which comprises no butt gap or comprises a specifically adjusted butt gap, is characterized in that the flange comprises material-displacing recesses at least in the metallic layer at at least two points distributed over the flange in the circumferential direction.

[0024] The recesses preferably take the form of impressions.

[0025] The recesses are preferably located in the inner and/or outer surface of the flange.

[0026] In a further preferred embodiment, the recesses extend as far as into the outer edge of the flange. It has been demonstrated that the material-displacing recesses are most effective, the further they are formed towards the outside, when viewed in the radial direction. The number of recesses may be markedly reduced relative to the number of recesses which do not extend as far as into the outer edge of the flange.

[0027] The recesses preferably widen radially from the inside to the outside. In this way, greater material displacement is caused where the circumference becomes larger.

[0028] The recesses are preferably semicircular or wedge-shaped.

[0029] As an alternative or in addition to the widening of the recesses, it is advantageous for the recesses to increase in depth from the inside radially towards the outside, because the associated increase in material displacement takes account of the radially outward increase in circumference.

[0030] The recesses preferably extend radially over the entire width of the flange.

[0031] The bending die according to the invention is characterized in that elevations are provided at at least two points distributed over the end face in the circumferential direction of the end face. The elevations are preferably arranged equidistantly in the circumferential direction.

[0032] The elevations may exhibit a circular, oval or wedge-shaped structure.

[0033] It is also possible for the elevations to take the form of radially extending webs.

[0034] The elevations may be formed on the end face or take the form of exchangeable components which are inserted into the end face. Punches projecting relative to the end face are preferably inserted into the end face. It is thereby possible to arrange the bending die in variable manner and in this way to adapt it to various widths of flange, the diameter of the flanged bush remaining the same.

[0035] The punches which may be inserted are preferably pins, which are inserted into corresponding drill holes in the end face of the bending die.

[0036] The bending device according to the invention comprises a bending die and a pressure plate acting on the bush edge to be bent round, wherein the bending die and/or the pressure plate comprise elevations on the surface facing the bush edge.

[0037] Exemplary embodiments of the invention are explained more fully below with reference to the drawings.

[0038] In the drawings:

[0039]FIG. 1 shows a conventional flanged bush with a flange according to the prior art,

[0040]FIG. 2 is a plan view of a first embodiment of a flanged bush according to the invention,

[0041]FIG. 3 is a plan view of a further embodiment of a flanged bush according to the invention,

[0042]FIG. 4 is a plan view of a third embodiment of a flanged bush according to the invention,

[0043]FIG. 5 shows a section through the flanged bush shown in FIG. 4, along line V-V,

[0044]FIG. 6 shows a section through a flanged bush according to a further embodiment,

[0045]FIG. 7 shows a vertical section through a bending device and

[0046]FIG. 8 is a plan view of a bending die with flanged bush inserted therein.

[0047]FIG. 1 shows a conventional flanged bush 1, which comprises a cylindrical bush body 2 and a single flange 3 formed thereon, having been produced by bending round of the bush edge. As a result of the production process, the flanged bush 1 comprises a considerable butt gap 5.

[0048]FIG. 2 is a plan view of a flanged bush 10 according to the invention, produced by the method according to the invention. This flanged bush 10 likewise has a cylindrical bush body 12 and a single flange 13, which comprises material-displacing recesses 16 on the inner surface 14 of the flange 13 at a plurality of equidistant points in the circumferential direction. In the embodiment of FIG. 2 shown here, the material-displacing recesses are semi-circular in form, such that the recesses widen radially from the inside outwards. The recesses are applied in such a way that they extend as far as into the outer edge 15 of the flange 13. The flanged bush 10 exhibits a closed butt joint 11.

[0049]FIG. 3 is a plan view of a flanged bush 10 according to a further embodiment. In contrast to FIG. 2, the material-displacing recesses 16′ are wedge-shaped and extend over the entire width of the flange. The wedge-shaped or V-shaped configuration of the recesses 16′ likewise widens radially from the inside outwards.

[0050]FIG. 4 shows a further embodiment of a flanged bush 10, wherein the equidistantly arranged material-displacing recesses 16″ are rectangular in plan view. The special feature of these material-displacing recesses 16″ is that the depth of the recesses increases radially from the inside outwards. This is visible in FIG. 5, which shows a section along line V-V of the flanged bush shown in FIG. 4. The flanged bush shown in FIG. 5 has a metallic backing material 17 and an overlay 18, which is applied to the outer surface 19 of the flanged bush. The recesses 16″ are formed on the inner surface 14 of the flange 13, such that the overlay 18 is not impaired.

[0051]FIG. 6 is a sectional view of a further embodiment of a flanged bush. The bush is again a two-layer flanged bush, wherein, however, the recesses 16′″ are formed in the outer surface 19 of the flange 13. The recesses extend so far into the flange material that the material displacement affects the metallic backing material 17.

[0052]FIG. 7 shows a vertical section through a shaping device 20, which consists substantially of an upper pressure plate 21, a bending die 22 and a lower pressure plate 23. Instead of a lower pressure plate 23, the bending die 22 may also comprise a shoulder inside the bush receptacle 25, on which rests the lower end face of the bush. In a first method step, the flange 3 may be pre-bent in the manner illustrated here, such that only post-bending has still to be performed with the pressure plate 21. The flange 13 is bent round in the direction of the arrows, such that the inner surface 14 is pressed onto the elevations 24 arranged on the end face 26 of the bending die 22, thereby forming the material-displacing recesses.

[0053] In the embodiment shown here, the elevations 24 are web-shaped in form and extend radially over the entire width of the end face 26 of the bending die 22. It is thereby possible to provide flanged bushes having flanges 13 of different widths with the material-displacing recesses according to the invention, without the bending die 22 having to be exchanged or reset. The wide arrows indicate the pressing direction, if the shaping device 20 is arranged in a press for example.

[0054]FIG. 8 shows a plan view of a bending die 22 with an already shaped flanged bush 10. In the case of this bending die, the elevations 24 are formed by pins 27 inserted into the end face 26. This die may for example be used to produce the flanged bush shown in FIG. 2.

Reference Numerals

[0055]  1 Flanged bush  2 Cylindrical bush body  3 Flange  4 Butt gap 10 Flanged bush 11 Butt joint 12 Cylindrical bush body 13 Flange 14 Inner surface 15 Outer edge of the flange 16, 16′, 16″, 16″′ Material-displacing recess 17 Metallic backing layer 18 Plastics overlay 19 Outer surface 20 Bending device 21 Upper pressure plate 22 Bending die 23 Lower pressure plate 24 Elevation 25 Bush receptacle 26 End face 27 Pin 

1. A flanged bush, in particular a flanged bush for plain bearings, with at least one flange formed thereon, the flanged bush comprising at least one metallic layer, characterized in that the flange (13) comprises material-displacing recesses (16, 16′, 16″, 16′″) at least in the metallic layer (17) at at least two points distributed over the flange (13) in the circumferential direction.
 2. A flanged bush according to claim 1, characterized in that the recesses (16, 16′, 16″, 16′″) take the form of impressions.
 3. A flanged bush according to one of claims 1 or 2, characterized in that the recesses (16, 16′, 16″, 16′″) are located on the inner surface (14) and/or the outer surface (19) of the flange (13).
 4. A flanged bush according to one of claims 1 to 3, characterized in that the recesses (16, 16′, 16″, 16′″) extend as far as into the outer edge (15) of the flange (13).
 5. A flanged bush according to one of claims 1 to 4, characterized in that the recesses (16, 16′, 16″, 16′″) widen radially from the inside outwards.
 6. A flanged bush according to one of claims 1 to 5, characterized in that the recesses (16, 16′, 16″, 16′″) are semicircular or wedge-shaped.
 7. A flanged bush according to one of claims 1 to 6, characterized in that the width of the recesses (16, 16′, 16″, 16′″) increases radially from the inside outwards.
 8. A flanged bush according to one of claims 1 to 7, characterized in that the recesses (16, 16′, 16″, 16′″) extend radially over the entire width of the flange (13).
 9. A method for producing flanged bushes, in particular flanged bushes for plain bearings, with at least one flange, in which a bush is made from a prefabricated strip portion comprising at least one metallic layer by shaping methods, in particular wrapping, the edge being bent round to form the flange, characterized in that, at at least two points distributed around the flange in the circumferential direction, material-displacing recesses are formed at least in the metal layer.
 10. A method according to claim 9, characterized in that the recesses are produced by stamping.
 11. A method according to one of claims 9 or 10, characterized in that the recesses are formed in the inner surface and/or the outer surface of the flange.
 12. A method according to one of claims 9 to 11, characterized in that the recesses are produced by bending round the bush edge.
 13. A bending die for producing one or two flanges on a bush, having a bush receptacle, wherein at least one of the end faces surrounding the bush receptacle forms a bearing surface for the flange, characterized in that the end face (26) comprises elevations (24) at at least two points distributed over the end face (26) in the circumferential direction.
 14. A bending die according to claim 13, characterized in that the elevations (24) are arranged equidistantly in the circumferential direction.
 15. A bending die according to claim 13 or claim 14, characterized in that the elevations (24) have a circular, oval or wedge-shaped contour.
 16. A bending die according to one of claims 13 to 15, characterized in that the elevations (24) are radially extending webs.
 17. A bending die according to one of claims 13 to 16, characterized in that the elevations (24) are formed on the end face (26).
 18. A bending die according to one of claims 13 to 16, characterized in that punches projecting relative to the end face (26) are inserted into the end face (26).
 19. A bending die according to claim 18, characterized in that the punches are pins (27).
 20. A bending device having a bending die and a pressure plate acting on the bush edge to be bent round, characterized in that the bending die (22) and/or the pressure plate (21) comprises elevations (24) on the surface facing the bush edge. 